JavaScript Date Methods

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Date methods let you get and set date values (years, months, days, minutes, seconds, milliseconds)

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Date Get Methods

Get methods are used for getting a part of a date. Here are the most common (alphabetically):

Method	Description
getDate()	Get the day as a number (1-31)
getDay()	Get the weekday as a number (0-6)
getFullYear()	Get the four digit year (yyyy)
getHours()	Get the hour (0-23)
getMilliseconds()	Get the milliseconds (0-999)
getMinutes()	Get the minutes (0-59)
getMonth()	Get the month (0-11)
getSeconds()	Get the seconds (0-59)
getTime()	Get the time (milliseconds since January 1, 1970)

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The getTime() Method

getTime() returns the the number of milliseconds since 01.01.1970:

Example

<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getTime();
</script>

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The getFullYear() Method

getFullYear() returns the year of a date as a four digit number:

Example

<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getFullYear();
</script>

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The getDay() Method

getDay() returns the weekday as a number (0-6):

Example

<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getDay();
</script>

You can use an array of names, and getDay() to return the weekday as a name:

Example

<script>
var d = new Date();
var days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
document.getElementById("demo").innerHTML = days[d.getDay()];
</script>

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Date Set Methods

Set methods are used for setting a part of a date. Here are the most common (alphabitically):

Method	Description
setDate()	Set the day as a number (1-31)
setFullYear()	Set the year (optionally month and day yyyy.mm.dd)
setHours()	Set the hour (0-23)
setMilliseconds()	Set the milliseconds (0-999)
setMinutes()	Set the minutes (0-59)
setMonth()	Set the month (0-11)
setSeconds()	Set the seconds (0-59)
setTime()	Set the time (milliseconds since January 1, 1970)

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The setFullYear() Method

setFullYear() sets a date object to a specific date. In this example, to January 14, 2020:

Example

<script>
var d = new Date();
d.setFullYear(2020, 0, 14);
document.getElementById("demo").innerHTML = d;
</script>

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The setDate() Method

setDate() sets the day of the month (1-31):

Example

<script>
var d = new Date();
d.setDate(20);
document.getElementById("demo").innerHTML = d;
</script>

The setDate() method can also be used to add days to a date:

Example

<script>
var d = new Date();
d.setDate(d.getDate() + 50);
document.getElementById("demo").innerHTML = d;
</script>

	If adding days, shifts the month or year, the changes are handled automatically by the Date object.

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Date Input - Parsing Dates

If you have an input value (or any string), you can use the Date.parse() method to convert it to milliseconds.

Date.parse() returns the number of milliseconds between the date and January 1, 1970:

Example

<script>
var msec = Date.parse("March 21, 2012");
document.getElementById("demo").innerHTML = msec;
</script>

You can then use the number of milliseconds to convert it to a date object:

Example

<script>
var msec = Date.parse("March 21, 2012");
var d = new Date(msec);
document.getElementById("demo").innerHTML = d;
</script>

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Compare Dates

Dates can easily be compared.

The following example compares today's date with January 14, 2100:

Example

var today, someday, text;
today = new Date();
someday = new Date();
someday.setFullYear(2100, 0, 14);

if (someday > today) {
    text = "Today is before January 14, 2100.";
} else {
    text = "Today is after January 14, 2100.";
}
document.getElementById("demo").innerHTML = text;

	JavaScript counts months from 0 to 11. January is 0. December is 11.